Geographic distribution of Phalloceros Eigenmann, 1907 (Cyprinodontiformes, Poeciliidae) in the Ilha Grande Bay Hydrographic Region, Rio de Janeiro, Brazil

The diversity and geographic distribution of Phalloceros Eigenmann, 1907 in the Ilha Grande Bay Hydrographic Region, in southeastern Brazil, is investigated. Examination of 81 samples revealed the presence of 5 species in the region: Phalloceros anisophallos Lucinda, 2008, P. aspilos Lucinda, 2008, P. enneaktinos Lucinda, 2008, P. harpagos Lucinda, 2008, and P. tupinamba Lucinda, 2008. Phalloceros harpagos and P. tupinamba are recorded for the first time in the area. The geographic ranges of P. anisophallos and P. enneaktinos are expanded. The 5 species belong to 3 distinct morphologies of the female urogenital papilla. Species from these distinct morphological lineages may occur sympatrically, but species within the same lineage are always allopatric. A key for the identification of these species is provided